Integral key plate for key cases

ABSTRACT

A key head for key cases formed of a unitary plate of spring metal having a tubular key loop retainer formed along its upper edge with laterally spaced slots opening into the tubular retainer and terminating at the inner ends thereof in enlarged access holes for insertion and removal of the head portion of a key loop. Spring fingers, struck from the plate, curve upwardly uniformly about a predetermined radium with their outer ends of a step configuration extending into the tubular retainer through said access holes. Each step portion blocks the insertion and removal of key loops from the key head and is disposed to hold the major portion of the head above said access holes serving as actuating means for the deflection of each spring finger by the head of a key loop for removal from the key head and reinsertion therein.

[ 51 May 15,1973

1541 INTEGRAL KEY PLATE FOR KEY CASES [75] Inventor: Douglas J. Broughton, Agawam,

Mass.

[73] Assignee: Buxton,

Mass.

[22] Filed: Apr. 14, 1972 [21] Appl. No.: 244,033

Incorporated, A gawam [52] US. Cl. ..70/456 B, 70/458 Primary ExaminerRobert L. Wolfe Attorney-Alonzo L, Neal, et a].

[57] ABSTRACT A key head for key cases formed of a unitary plate of spring metal having a tubular key loop retainer formed along its upper edge with laterally spaced slots opening into the tubular retainer and terminating at the inner ends thereof in enlarged access holes for insertion and removal of the head portion of a key loop. Spring fingers, struck from the plate, curve upwardly uniformly about a predetermined radium with their outer ends of a step configuration extending into the tubular retainer through said access holes. Each step portion blocks the insertion and removal of key loops from the key head and is disposed to hold the major portion of the head above said access holes serving as actuating means for the deflection of each spring finger by the head of a key loop for removal from the key head and reinsertion therein.

4 Claims, 3 Drawing Figures Shears ..70/456 B PATENTED HAY! 51975 M nllmlhl INTEGRAL KEY PLATE FOR KEY CASES BACKGROUND While efficiently operating key heads have been available for many years, in general these have been fabricated of separate components, such as a key head plate and locking bar or plate. Attempts to produce a unitary key head which combines the function of the locking bar element and key head plate have invariably left much to be desired from the standpoint of durability, operating effectiveness and simplicity of constructron.

The principal object of this invention is to provide a simplified, effective and economical key head construction formed of a unitary metal plate wherein the key loop retaining members are curved spring members which are integral with and struck from a spring metal plate.

A further object of this invention is to provide a key head of the above type in which key loops are securely held by said key head until intentionally released by the simple deflection of said spring elements.

The above and other objects and advantages of this invention will be more readily appreciated from the following description and with reference to the accompanying drawings, in which FIG. 1 is a partial perspective view showing a key case containing a key head embodying the present invention;

FIG. 2 is a plan view, on an enlarged scale, showing a metal plate stamping used in forming a key head embodying this invention; and

FIG. 3 is an enlarged cross sectional view, on an enlarged scale, taken along line 33 of FIG. 1.

Referring in detail to the drawings, in FIG. 1 is shown a key case 4 in which is carried a key head 6 affixed adjacent the upper edge of a central key case panel 8. Two overlapping closure panels or flaps l and 12 extend from opposite side edges of the central panel 8 and may be provided with registrable snap fastener elements, not shown, for releasably maintaining the overlapped edges of the flaps in closed relationship. The

key head 6 is attached to the case by any suitable means, such as rivets 14, which extend through the material forming the case and holes 16 (FIG. 2) provided in the key head.

Depending from the key head are a plurality of key hangers or loops 18, one of which is shown in FIG. 1. Each loop is formed from a spring metal wire stock having a diameter of about 0.055 inch bent to form a key receiving loop portion 20, a shank portion 22 and a generally spherical head 24 (FIG. 3), of a diameter about 0.1 inch which fits within to a tubular retainer portion of the key head, as will be hereinafter more fully described.

The shank or neck portion 22 of the key loop extends generally along a straight line from the loop to the ball 24, and has a length not less than the inner diameter of the tubular retainer portion of the key head. This relationship insures against the loop opening or mouth portion, as at 25, being accidentally lodged and stuck in the axially spaced, circumferential slots 26 of the key head. From the shank portion the loop extends downwardly and curves back upon itself terminating at the mouth 25 where the outer end of the loop is disposed in closely spaced relation to the lower end of the shank. The outer end of the loop wire flares outwardly at the mouth 25 to facilitate insertion of the key eyelet between the shank and the free end of the key loop.

The key head 6 includes an upper tubular portion 28 which, as shown, may be about 0.22 inch in diameter, and a base or plate portion 30, the undersurface of which abuts the key case. In accordance with this invention, the key head is of integral construction formed from a unitary blank, as shown generally at 32 in FIG. 2. The blank is formed of any suitable annealed spring steel, such as commercially available by designation: SAE No. 1070, heat treating formula RC: 45-47. The gauge of blank or plate 32 may be about 0.016 to 0.022 inch, preferably about 0.018. Adjacent the lower edge of the blank the holes 16 are provided by which the plate may be riveted to the central panel of the key case.

Laterally spaced across the width of the opposite edge of the plate are the slots 26, which may be on the order of 0.057 inch in width. Each of the plurality of elongated slots 26 terminates at its outer end in an enlarged access hole or opening 27 of generally circular cross section of sufficient diameter, such as about 0.1 I2 inch, to accommodate the free and easy passage therethrough of the key loop head 24. Each slot 26 has generally straight, parallel side edges and a length of about one-third the dimension of the plate 32 measured in the same direction.

Intermediate the location of the holes 16 and the inner ends of the elongated slots 26, the blank 32 includes a plurality of laterally spaced cantilever spring members or fingers 36, each of which is disposed in axial alignment with a corresponding slot 26. The spring members 36 are struck from the blank and extend upwardly on a smoothly curved arcuate path, as shown generally in FIG. 3. It has been found that for a spring'of the type shown a radius of about 0.725 to 0.775 provides a suitable spring curvature. Each spring tapers in width uniformly from its base to tip being of generally conical configuration. These spring f ngers flex uniformly when actuated and are, therefore, extremely durable and essentially breakage free with normal usage over the reasonable life expectancy of such key cases. The side edges of each spring element are relieved as shown at 38 to clear the edges of the underlying opening from which the spring is struck and deflected before the plate is heated and tempered. Where 'it is desired to avoid relieving the side edges of the spring members, a greater spring curvature may also be used so that the spring at its root more sharply clears the plate than in the embodiment shown. From its inner end, each spring extends curvilinearly upward to a step or shoulder 40, the upper surface of which extends slightly downward to the terminal end thereof. These steps provide means by which each spring may be actuated or tensioned by downward deflection thereof, thereby permitting ball 24 to be removed from the key head cylinder 28. The step 40 also serves to support ball 24 (FIG. 3) within the tubular portion of the key head, as shown in FIG. 3, so that at least about half the ball diameter is held above the upper ends 41 of the access holes 27 and thus the ball, which is substantially larger than the width of circumferential slots 26, is positively confined within the cylinder 28 of the key head. The step portion 40 of each spring finger is located at a sufficient height above the upper surface of blank 32 and its inner end is disposed within the inner surface of the tubular portion 28 of the key head, as shown in FIG. 3, so that the key loop head is held toward the upper side of the key head cylinder.

The key head is formed into the desired configuration from the annealed steel plate 32 and thereafter the key head is heat treated and tempered at the appropriate temperatures for the selected steel. The upper edge portion of the annealed plate 32 is formed by rolling into a tubular configuration, of preferably cylindrical cross section, with an edge 42 contiguous or in contact with the plate on each side of spring fingers 36, whereby outer ends of the spring fingers extend through the holes 27 formed along the upper edge of the plate. The access holes 27, as best shown in FIG. 3, accommodate the tip of each spring member from the start of the step 40 outwardly thereof. The end of each spring when in an unflexed condition, serves to block the enlarged access holes 27, thereby holding the ball 24 in the upper portion of the cylinder in registration with the slots 26.

When the key loops are in their normal depending relation, the head 24 rests against the step portion of the spring finger and cannot be unintentionally dislodged from the tubular head portion without the depression of the spring fingers. This is accomplished by grasping the key loop adjacent its outer end and using it in the manner of a lever by pressing its head 24 against the step portion 40 of the spring to deflect it downward sufficiently to clear the hole 27, thereby permitting radial outward removal of the key loop head through access hole 27. The key loop may be reinserted in the key head by reversing the above procedure, that is, the shank of the key loop is fitted into one of the slots 26 with the key loop preferably disposed above the cylinder 28 while the ball 24 is placed against the spring finger 36, immediately adjacent the lower side of the cylinder 28. Downward pressure on the key loop, used in the manner of a lever, will easily deflect the spring finger 36 downward, thus permitting the ball portion 24 thereof to snap radially into the key head through one of the access holes 27.

Having thus described this invention, what is claimed 1. Key head for key loops having a key retaining loop portion, a shank portion and an enlarged head comprising a unitary spring metal plate having a tubular key retainer formed adjacent one edge thereof with laterally spaced slots, greater in width than the diameter of the shank portion of said key loops but less than said head, opening circumferentially into said tubular retainer and terminating at the lower side thereof in access holes of a diameter larger than the head of said key loops, said holes facing the edge of said plate opposite the retainer, and cantilever spring elements extending upwardly and tapering in width from said plate to the outer ends which terminate within said tubular retainer extending through said access holes at sufficient height to block said access holes to prevent removal of a key loop head from the retainer without deflection of said spring element.

2. Key head for key loops as set forth in claim 1 in which each of said spring elements extends curvilinearly upward from the plate about a generally uniform radius of curvature.

3. Key head for key loops as set forth in claim 2 in which said spring elements have rectilinear side edges and taper uniformly in width from the base to the tip thereof and terminate in a step portion disposed within the tubular retainer of said key plate.

4. Key head as set forth in claim 3 in which said tubular retainer is of generally cylindrical cross section with one edge of said plate being rolled to form said retainer and having an inner diameter less than the length of the shank portion of the key loop, and in which each of said key loops include a spherical head, said step portion of said spring elements in an unflexed condition being disposed above said plate a sufficient height to hold the major portion of the spherical head above the upper edge of said access holes. 

1. Key head for key loops having a key retaining loop portion, a shank portion and an enlarged head comprising a unitary spring metal plate having a tubular key retainer formed adjacent one edge thereof with laterally spaced slots, greater in width than the diameter of the shank portion of said key loops but less than said head, opening circumferentially into said tubular retainer and terminating at the lower side thereof in access holes of a diameter larger than the head of said key loops, said holes facing the edge of said plate opposite the retainer, and cantilever spring elements extending upwardly and tapering in width from said plate to the outer ends which terminate within said tubular retainer extending through said access holes at sufficient height to block said access holes to prevent removal of a key loop head from the retainer without deflection of said spring element.
 2. Key head for key loops as set forth in claim 1 in which each of said spring elements extends curvilinearly upward from the plate about a generally uniform radius of curvature.
 3. Key head for key loops as set forth in claim 2 in which said spring elements have rectilinear side edges and taper uniformly in width from the base to the tip thereof and terminate in a step portion disposed within the tubular retainer of said key plate.
 4. Key head as set forth in claim 3 in which said tubular retainer is of generally cylindrical cross section with one edge of said plate being rolled to form said retainer and having an inner diameter less than the length of the shank portion of the key loop, and in which each of said key loops include a spherical head, said step portion of said spring elements in an unFlexed condition being disposed above said plate a sufficient height to hold the major portion of the spherical head above the upper edge of said access holes. 